Frost dates for Rexburg Madison Co Airport, ID
At Rexburg Madison Co Airport, the median last spring frost (32°F) is May 15 and the median first fall frost is Sep 23, for a typical growing season of 129 days. For a 90% chance that the last frost has passed, wait until Jun 3. Nearby ZIP codes are in USDA hardiness zones 5a to 5b.
- May 15Last spring frost (median)50% chance of 32°F after this date
- Jun 3Safer planting date10% chance of 32°F after this date
- Sep 23First fall frost (median)50% chance of 32°F by this date
- 129 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 19 | Jun 6 | Jun 23 |
| 32°F | May 1 | May 15 | Jun 3 |
| 28°F | Apr 17 | May 1 | May 13 |
| 24°F | Apr 1 | Apr 15 | May 2 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Aug 30 | Sep 10 | Sep 25 |
| 32°F | Sep 8 | Sep 23 | Oct 7 |
| 28°F | Sep 20 | Oct 5 | Oct 20 |
| 24°F | Oct 2 | Oct 19 | Nov 3 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 76 days | 96 days | 119 days |
| 32°F | 103 days | 129 days | 150 days |
| 28°F | 135 days | 157 days | 177 days |
| 24°F | 163 days | 184 days | 206 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 83460 | 5a | -20 to -15°F | 3 km |
| 83440 | 5a | -20 to -15°F | 3 km |
| 83448 | 5a | -20 to -15°F | 8 km |
| 83451 | 5a | -20 to -15°F | 14 km |
| 83438 | 5a | -20 to -15°F | 14 km |
| 83434 | 5a | -20 to -15°F | 18 km |
| 83442 | 5b | -15 to -10°F | 23 km |
| 83445 | 5a | -20 to -15°F | 23 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00094194, at 43.8339, -111.8045, elevation 1481 m (4,858 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 181.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Rexburg Byu Idaho (3 km)
- Sugar City (8 km)
- Saint Anthony (17 km)
- Rigby (20 km)
- Ashton 1n (38 km)
- Idaho Falls - Kifi (39 km)
- Hamer 4 NW (40 km)
- Idaho Falls Fanning Field (41 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.